Dimeric mixed-ligand copper(II) complexes with di-imines and salicylaldehydate

Abstract

The variable-temperature (2–298 K) magnetic susceptibility, electrochemical, and spectral properties of three binuclear copper(II) complexes [{CuL(sal)}₂][ClO₄]₂ are reported. Each copper(II) ion of the binuclear complex is co-ordinated to a di-imine molecule L [bis(2- pyridyl)amine, 2,2′-bipyridine, or 1,10-phenanthroline], and a salicylaldehydate anion (sal) bridging the two metal ions through the phenoxide oxygen atom. At room temperature the complexes show a normal magnetic moment, µ= 1.8–1.9. However, antiferromagnetic interactions are found when susceptibility data are taken at temperatures down to ca. 2 K. Magnetic, electrochemical, and spectral properties are discussed in relation to the known solid-state geometry of the complexes.